With 2.4 GHz Radio Frequency technology, the Adesso® iMouse™ E55 Wireless Vertical Ergonomic Mouse provides you with wireless convenience and the freedom of a smooth connection for up to a 30-foot range without tangled cables. This ergonomic mouse is designed with a vertical orientation and a contoured shape that provides a uniquely comfortable user experience. With this wrist-friendly contour support, you will hold your mouse in a comfortable vertical position. The advanced Optical Sensor technology keeps the mouse precisely on point and lets you work on most glass, wood, marble, and leather surfaces without a need of a mouse pad. Simply plug the USB receiver into any available USB port and insert 2 AAA batteries and be ready to enjoy the freedom of a comfortable and wireless mouse experience!